Science Sheet

Transcription

1 Science Sheet 9. What are a two features left behind by retreating glaciers? Name: Date: Instructions: Read pages and answer the following questions in point form 1. What does the continental drift theory state? 10. What is Paleoglaciation? 11. a) Why were scientists puzzled by evidence of glaciers in India and Africa? 2. What gave Wegener his first piece of evidence for continental drift? b] How is this evidence explained? 3. What is Pangaea? 4. What is a better way to align the continents other than matching up their continental edges? 12. a) Explain why coal deposits in Antarctica are hard to account for with today's climate there. 5. What are three other clues that Wegener used as evidence for continental drift? b) What's the best explanation for the Antarctic coal deposits? 13. Why was Wegener's theory not accepted immediately? 6. What did Wegener note about certain mountain ranges and rock ages on opposing continents? 14. What did scientists NOT KNOW about the earth's surface in Wegener's time? 7. Explain how the appearance of the Mesosaurus fossil in South America and Western Africa supports the concept of continental drift. 15. What are tectonic plates? 8. a) Which continents is the Glossopteris fossil found on? 16. Describe volcanoes. b) Explain how thisprovides evidence for the existence of Pangaea. 17. Describe earthquakes.

2 18. Where do earthquakes and volcanoes mostly occur in relation to tectonic plates? 27. What did scientists notice about the direction of magnetic fields in iron containing rocks on the bottom of the Atlantic Ocean? 19. What were Oceanographers amazed to find on the bottom of the Atlantic Ocean? 28. Make a sketch of figure on page 512 and describe the process of sea floor spreading using your diagram. On your diagram, label the following things: Newer Rock, Older Rock, Magma. 20. What did scientists notice about the age of rocks near the Mid Atlantic Ridge? Also, put arrows on your diagram that show the direction the sea floor is moving. 21. What was noticed about the amount of sediment on the ocean floor as you moved away from the Mid Atlantic Ridge? 22. How is the earth like a bar magnet? 23. Why do compasses point north? 24. Describe magnetic reversal and explain what scientists think causes it to occur. 29. What is a hot spot? 25. **If magnetic reversal occurred right now, what direction would a compass point? 26. What is Paleomagnetism?

3 Early maps of the world caused Wegener to propose the theory. The continents looked as though they might fit together like. The original supereontinent was named P by Wegener. Wegener also realized that other evidence also supported his theory. * There were matching geologic features and on different continents. There were matching like Mesosaurus, on different continents. There was evidence of glaciers on. continents. See pages fel MeGflr* HB fiyvaon i how entire continents could change locations. New scientific equipment allowed scientists to measure the slow but steady drift of Earth's p!ates.» It was noted that and volcanoes appear In certain patterns along the edges of tectonic plates. * Mapping of the ocean floor revealed the Ridge, a long mountain range running down the middie of the Atlantic Ocean. i ÿ Rocks taken from the Mld-Atlantlc Ridge were than other j ocean rocks. ÿ Paleomagnetlsm shows that j magnetic rocks along the j \ ridges are striped with j' j ^ magnetic fields. \ Seepages610-EM I ' fc! tax3faivhftpf+?*o<i 2t T

4 Clc? Name ' Date Activ..., 1 Use with textbook pages Evidence for continental drift Vocabulary "'Section 12.1 : i Hess suggested that magma rose to form new at certain places. Magma (melted rock) rises and falls like and liquids. The convection currents of magma formed a spreading ridge where they broke through Earth's. Like a "new crust" belt Magnetic striping of basalt rock shows long stripes of new rock moving away from ocean ridges and also reveals the of Earth's magnetic field at that time. Wilson then. the Ideas of Wegener and Hess Into the plate tectonic theory. * Geologic hot spots are anywhere. _a rises to Earth's surface. Take Che Sectinn T7.1 See pages ^ fo UcOrsw HS flyman 2 ancient glaciers fossils geological structures hot spot magma magnetic reversal Mid-Atlantic Ridge Use the terms in the vocabulary box to fill in the blanks. Each term may be used only once. mountain ranges Pangaea plate tectonic theory spreading ridge supercontinent tectonic plates 1. Alfred Wegener proposed that, millions of years ago, all the continents were joined as a 2. The name given to this giant land mass is 3. Wegener compared, and evidence of on different continents. 4. Since rocks found in Newfoundland are the same type and age as rocks found in Greenland, Ireland, Scotland, and Norway, it would appear that the world's major were continuous when the continents were joined. 5. The surface of the Earth is broken into large, rigid, movable that move over a layer of partly molten rock. 6. in the, scientists found that as distance increases from the centre of the ridge, the rocks are older and the ocean sediment is thicker. 7. Using a magnetometer, scientists fouhd a pattern of 1 in the iron-containing minerals on both sides of the Mid-Atlantic Ridge. 8. Harry Hess suggested that rises because it is less dense than the material that surrounds it. 9. At a the magma breaks through the Earth's surface, where it cools and hardens, forming a new sea floor. 10. J. Tuzo Wilson suggested that chains of volcanic islands were formed when a tectonic plate passed over a stationary 11. The is the unifying theory of geology. 210 MHR Section 12.1 Evidence for Confinental Drift 20QB McGraw-Hill Ryerson Umited

5 Name Date Applying Knowledge Section 12.1 Name Date Inte Ulusti_...iiis Section 12.1 L/se with textbook pages Theories related to continental drift Various pieces of evidence have been gathered by scientists to explain the underlying theories of geology. Alfred Wegener, Harry Hess, and J. Tuzo Wilson are some of the scientists who proposed explanations of phenomena they had observed. Fill in the following table comparing the main points of evidence presented by each theory. Continental drift Paleomagnetism j Proposed by: ; Main points: Main points: Use with textbook pages Visual observations supporting continental drift Illustrations can demonstrate some of the major points related to the concepts presented in this chapter. Refer to the diagrams on the left, when answering the questions below. AFRICA i SOUTH A j'fjoia AMERICA >MERlCA,.i t ; \ b-ty?- ' -V IN i y,1, " ^wtarcticav'1, i'austraua What evidence did Wegener use for his explanations of the existence of Pangaea? 2. f-t Normal magnetic polarity Reverse magnetic polarity (a) How were these magnetic patterns measured? Sea floor spreading Plate tectonic theory Proposed by: ' Proposed by: Main points: ' Main points: (b) What do these patterns show? Orientation of Earth's Magnetic Field How were the Hawaiian Islands formed? Hawaiian Islands 2008 McGraw-Hill Rysrson Limlled Section 12.1 Evidence for Continental Drift MHR 212 MHR Section 12.1 Evidence for Continental Drift 2008 McGraw-Hill Ryerson Umltod (k)

6 Section 12.1 Evidence for Continental Drift Check Your Understanding 9. Why does the thickness of ocean floor sediments increase the farther they are from a ridge? 10. How does sea floor spreading explain the movement of tectonic plates? Checking Concepts 1. What is a supercontirent? 11. Suppose a geologist is studying two distinct areas next to a spreading ridge. The magnetic direction of the minerals in the oldest area is opposite to the magnetic direction of minerals in the newest area. (a) Which area Is closest to the centre of the ridge, the older or newer area? Explain. 2. List three pieces of evidence that Indicate that continental drift occurred In the distant past. (b) What can the geologist conclude about Earth's magnetic field during the time when the two areas formed? 3. Briefly describe two pieces of evidence that suggest that Antarctica was once located farther from the South Pole than It Is today. 12. In a few sentences, explain how Information from paleogladation and paleomagnetism support the Idea that continental plates have moved over the past several miliion years. 4. What is sea floor spreading? 5. What is the relationship between continental drift and earthquakes? Pesiisb cind HE fj&ct 6. Describe the theory of plate tectonics In your own words. Understanding Key Ideas A marsupial is a type of mammal that carries its undeveloped young in an abdominal pouch. Scientists believe that many kinds of marsupials once lived throughout the world. Today, however, many marsupials are found only In Australia. How does the continental drift theory explain the modem distribution of marsupials? Use the diagram shown here to help you answer this question., 7. Coal deposits form when plant matter sinks underwater, begins to decompose, and is compressed. Explain how the presence of coal deposits In Siberia, northern Canada, and the Antarctic support the continental drift theory. 8. Despite the evidence Wegener found to support the continental drift theory, the scientific community of his day thought the Idea of moving continents was ridiculous. What crucial question couid Wegener not answer that might have changed other scientists' minds? 'V'r.'w 1;:H itycrson "'OOS r.c ^.-ioi'cu l'- M,<rn\v llhi itvitsor.?00s UC Sc.ionco 1 i'

7 Name:. Date: Name Bill Nye: Earth's Crust Date Period 1. The Earth's is a thin layer of rock that surrounds the Earth. 2. The layers of the Earth from the center are the,,, and. 3. If the Earth were like an egg, the crust would be as thick as the 4. Mt. St. Helens was erupting as the early settlers moved in from the year until. 5. The "lava" was made in the laboratory by mixing and which produced gas. 6. A is like a volcano, except it is boiling water. 7. Tectonic is from the Latin word meaning. 8. means "whole Earth". 9. Where the plates spread apart, we get. 10.Where the plates come together, we get. 1 l.north America is moving away from Europe about inch(es) per year. 12. are hollowed out spaces in the Earth's crust. 13.The Earth's core is kilometers in diameter. Science Movie Worksheets - httpi/avww.newyorkscieiicetenciicr.coni/movies 2 Continents Adrifb An Introduction to Continental Drift and Plate Tectonics 1. In the early 1900's, a German Scientist named believed that the continents had once been joined into a super-continent called Pangea. a} Isaac Newton c] Alfred Wegener b] JohnDalton d] Dmitri Mendeleev 2. The super-continent Pangea existed a) 65 million years ago c) '500 million years ago b) 200 million years ago d) 1 billion years ago 3. Evidence for continental drift includes: a} Thejigsawpuzzlefitofcontinents b) Identical fossils were found in South America and Africa c) Plant fossils were found in cold Arctic regions, where they could not live today d) Ali of the above 4. The underwater mountain range that runs down the middle of the Atlantic ocean is called the: a] The Great Spine of the Atlantic b} Volcano Alley cj The Seismic Range d) The Mid-Atlantic Ridge 5. Scientists have discovered that, in the middle of the Atlantic Ocean, there Is a crack and the sea floor is spreading. They found that: a] Older rocks are located closer to the middle of the crack b) Older rocks are located further away from the middle of the crack c) Older rocks are mixed randomly with newer rocks near the crack 6. What evidence did scientists use to learn that the Earth's crust was broken into pieces? a] Evidence from magnetic interference b) Evidence from drilling into glaciers cj Evidence from earthquakes 7. As the seafloor spreads, what is happening? a] North America is moving away from Asia at a divergent plate boundary b) North America is moving away from Asia at a convergent plate boundary c) North America is moving towards Asia at a divergent plate boundary d] North America is moving towards Asia at a convergent plate boundary 8. Sometimes when plates collide, one plate will go under the other. This is called: a] Conduction b) Induction cj Subduction d] Nanoduction

8 9. What happens e. jnvergent plate boundary? a] Plates crash into each other b) Plates that carry oceans dive under plates that carry continents c) Plates that carry continents dive under plates that carry oceans d] Both "a" and "b" are correct 10. What happens at a transform plate boundary? a) Plates move towards each other b) Plates move apart from each other c) Plates slide past each other d) Hone of the above 11. When two plates carrying continents collide, rock material is pushed up high into the air. This results in the formation of: a) mountains b) icebergs c] hurricanes d] rainforests 12. What types of fossils have been found in almost every mountain range in the world? a) Fossils of saber-toothed tigers b) Fossils of lystrosaurs c) Fossils of sea life d) Fossils of apatosaurs 13. What do scientists think will happen about 100 million years from now? a) All earthquake and volcano activity will stop b) All magma within the Earth will cool and solidify c) The continents will stop moving d) The Earth will escape the sun's gravity and spin off into outer space Summary Questions: 14. Describe, in your own words, some of the evidence for continental drift. 15. Name and briefly describe the 3 types of plate boundaries.